sched: mix tasks and groups

This patch allows tasks and groups to exist in the same cfs_rq. With this
change the CFS group scheduling follows a 1/(M+N) model from a 1/(1+N)
fairness model where M tasks and N groups exist at the cfs_rq level.

[a.p.zijlstra@chello.nl: rt bits and assorted fixes]
Signed-off-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 9 insertions, 6 deletions

diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c
index 8ff824565e06..201a69382a42 100644
--- a/kernel/sched_rt.c
+++ b/kernel/sched_rt.c
@@ -374,11 +374,15 @@ static void update_curr_rt(struct rq *rq)
         curr->se.exec_start = rq->clock;
         cpuacct_charge(curr, delta_exec);
 
-        spin_lock(&rt_rq->rt_runtime_lock);
-        rt_rq->rt_time += delta_exec;
-        if (sched_rt_runtime_exceeded(rt_rq))
-                resched_task(curr);
-        spin_unlock(&rt_rq->rt_runtime_lock);
+        for_each_sched_rt_entity(rt_se) {
+                rt_rq = rt_rq_of_se(rt_se);
+
+                spin_lock(&rt_rq->rt_runtime_lock);
+                rt_rq->rt_time += delta_exec;
+                if (sched_rt_runtime_exceeded(rt_rq))
+                        resched_task(curr);
+                spin_unlock(&rt_rq->rt_runtime_lock);
+        }
 }
 
 static inline
@@ -477,7 +481,6 @@ static void dequeue_rt_entity(struct sched_rt_entity *rt_se)
  * entries, we must remove entries top - down.
  *
  * XXX: O(1/2 h^2) because we can only walk up, not down the chain.
- *      doesn't matter much for now, as h=2 for GROUP_SCHED.
  */
 static void dequeue_rt_stack(struct task_struct *p)
 {